DescriptionGNOME Calendar is a simple and beautiful calendar application designed
to perfectly fit the GNOME desktop. By reusing the components which the
GNOME desktop is build on, Calendar nicely integrates with the GNOME
ecosystem.

Log message:
Add COMPILER lines to c++ ports which currently use the default. Adjust
some existing COMPILER lines with arch restrictions etc. In the usual
case this is now using "COMPILER = base-clang ports-gcc base-gcc" on
ports with c++ libraries in WANTLIB.
This is basically intended to be a noop on architectures using clang
as the system compiler, but help with other architectures where we
currently have many ports knocked out due to building with an unsuitable
compiler -
- some ports require c++11/newer so the GCC version in base that is used
on these archirtectures is too old.
- some ports have conflicts where an executable is built with one compiler
(e.g. gcc from base) but a library dependency is built with a different
one (e.g. gcc from ports), resulted in mixing incompatible libraries in the
same address space.
devel/gmp is intentionally skipped as it's on the path to building gcc -
the c++ library there is unused in ports (and not built by default upstream)
so intending to disable building gmpcxx in a future commit.

Log message:
Stop setting CONFIGURE_STYLE in Makefile.inc but explicitely add it to ports
that need it; in the future more and more ports will move to meson build anyway.
I first though I'd set CONFIGURE_STYLE in gnome.port.mk but it's too fragile
(MODULES list must be sorted very carefully).
Less magic is good.
discussed with jasper@